The L50B is a Ø50mm sphere shaped Acoustic Pressure Equaliser, designed for use with 4003 and 4006 and A-B Stereo Kits.
It offers a strong on-axis boost and off-axis attenuation. Its dimensions accentuate the on-axis boost at lower frequencies and allow off-axis sources to be strongly attenuated above 1 kHz. This will give your recordings a more intense sensation of source clarity and presence, a marked increase in brightness, and extend the effective reach of your microphones.
You will also find that the L50B is particular useful for making recordings under reverberant conditions.